This invention relates to the alignment of optical components; for example, the alignment of an optoelectronic device to a lens.
In many applications the alignment of optical components along a light transmission axis is a formidable task. High precision mechanical equipment in conjunction with complex automation schemes and sophisticated search algorithms are often required to achieve tight alignment tolerances. For example, one way to align a light emitting diode (LED) to a lens, both in a device package, entails inserting a light fiber probe into the package and moving the LED, while it is energized to emit light, until the maximum intensity detected by the probe is located.
The search algorithms associated with this type of alignment process can be time consuming, with longer times required for LEDs having relatively narrow near-field emission patterns. For example, the alignment of some LEDs to lenses may take from tens of seconds to a few minutes with a mean in excess of one hundred seconds.
Similar comments apply to the alignment of a photodetector to a lens, although the larger active area of most photodetectors, as compared to most LEDs, alleviates some of the difficulty.
The primary difficulty with optimizing search algorithms, minimizing the number of moves required to align the optical components, is the lack of a true and convenient reference to which the movable component can be aligned.